TRANSACTIONS OF THE SECTIONS. 47 



From such data I conclude that we cannot apply to flat regions, in which water 

 has no abrading power, the same influence which it exerts in mountainous coun- 

 tries ; whilst we are also compelled to admit that the convulsive dislocations of 

 former periods produced many of those gorges in which our present streams 

 flow. To pass, indeed, from the environs of Bath and Bristol, and even from the 

 less distant Coalbrook Dale, you have only to contemplate the tract which lies 

 between Birmingham and Dudley, and endeavour to satisfy the mind as to the 

 processes by which it has been planed down before the surface was covered by 

 the Northern Drift ; for the great dislocations which this tract has undergone, 

 as proved by many subterraneous workings, must have left a highly irregular 

 surface, which was so levelled by some very active causes as to obliterate the 

 superficial irregularities corresponding with the interior disturbances. In short, what 

 was this great power of denudation which took place in a tract where there are no 

 mountains whence powerful streams descended, and in which there are no traces 

 of fluviatile action ? Must we not, in candour, admit that such denudation is as 

 difficult to account for as it is to explain by what possible gradual agency the vast 

 interior of the valley of elevation of the Weald of Sussex and Kent, and that of 

 the smaller valley of Woolhope in Herefordshire, have been so absolutelyand entirely 

 denuded of every fragment of the enormous masses of debris which must have 

 encumbered these cavities, as derived from the rocks which once covered them ? 

 Placing no stint whatever on the time which geologists must invoke to satisfy their 

 minds as to the countless ages which elapsed during the accumulations of sediment, 

 I reject as an assumption which is at variance with the numberless proofs of in- 

 tense disturbance, that the mechanical disruptions of former periods, and the over- 

 throw of entire formations, as seen in the Alps and many mountain-chains, can be 

 accounted for by any length of action of existing causes. 



But I must not wander further on, illustrating this principle, to which, as an old 

 practical geologist, I firmly adhere, namely, that in former periods there existed forces 

 which, though similar in kind, were of much greater intensity than those which 

 now prevail, and without which we in vain seek to account for the upheavals, 

 depressions, dislocations, and even many of the denudations of which the old 

 crusts of the earth exhibit such undeniable proofs. 



To turn, however, from these general views to the immediate prospects of this 

 Meeting, I must congratulate you on having here among the men of science 

 many of the good geologists who constitute the Natural-History Clubs, most of 

 which have arisen since the British Association met last at Birmingham. 



First in the number of such local associations let me mention the Club of the Mal- 

 vern Naturalists, so ably presided over by the Rev. W. Symonds. Many are the 

 valuable data which the researches of its president and members have brought to 

 light, in addition to the original sketches of that highly interesting tract by Mr. 

 Leonard Horner and myself, and to the more elaborate and finished work of Professor 

 Phillips, Among the last contributions, I must specially advert to a memoir by 

 Dr. Holl, in which he endeavours to prove that the lowest crystalline rock of the 

 Malvern Hills is the equivalent of the Laurentian system' of North America. 

 Although I was at first indisposed to admit the validity of his inference, and even 

 yet see objections to it, and incline rather to the belief that it is of a Lower 

 Cambrian age, I deem it fair to avow that, in a tract where all the lowest 

 Silurian rocks are exhibited, though in epitome only, it is possible that the 

 basement of that primitive Malvern series may be the equivalent of the vast 

 Laurentian of America, the north-west of Scotland, and of Bohemia, though in 

 mineral character there is not the resemblance I should expect to find. 



Then in Shropshire, the very kernel of the Silurian rocks of Britain, we have the 

 Caradoc Club, continually adding to*and illustrating all the phenomena around the 

 Wrekin and Caer Caradoc ; and the Oswestry and Welshpool Naturalists' Club, 

 whose Secretary is a zealous geologist, and, with his associates, diligently explores 

 the neighbourhood of Oswestry and Llangollen, to the geology of which he has 

 recently published a ' Guide.' 'in Herefordshire there is the Woolhope Naturalists' 

 Club, whose members claim, and occupy with zeal, all the fossil hunting-ground 

 to the south of the Caradoc, and range in their excursions from the beautiful 

 valley of elevation at Woolhope to Ludlow and its environs. 

 . Next, if we cross the valley of the Severn, or that which, in the geological 



